Conventionally, there are various types of post-installed anchors available which are each to be inserted and fixed in an anchor insertion hole formed in a structure such as an existing concrete structure. For example, JP 2012-233490A discloses a post-installed anchor which is formed by subjecting a single pipe material to pressure-forging and is a one-piece product including a first bolt part and a second bolt part connected by a connecting part. The first bolt part has a tapered part formed by pressure-forging to reduce the diameter of the pipe material. The second bolt part is shaped by pressure-forging to have four slits and a concavo-convex part at a bolt top, in which an inner circumferential wall in aback face area of the concavo-convex part serves as a guide face to be joined with an outer circumferential face of the tapered part. The connecting part is a vestige of forging to connect the first bolt part and the second bolt part at the bolt top, and is thin and rupturable.
Further, JP 2012-184581A discloses a post-installed anchor which includes a cylindrical body part, an expandable part having a plurality of slits formed on the tip side of the body part, leaving a prescribed interval in a circumferential direction and extending in an axial direction, a female screw formed in the inner surface of the expandable part, and a male screw body screwed with the female screw. The inner surface of the expandable part in which the female screw is formed is tapered toward the side at which the expanded expandable part closes as the male screw body is retracted. By screwing the male screw body into the female screw and advancing the male screw body toward the tip side of the body part, the expandable part is opened and expanded, and the expandable part closes as the male screw body is retracted.